Servicing equipment for vehicles



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59 zqoazl sw Dec. 1, 1936. F. E. WOLD SERVICING EQUIPMENT FOR VEHICLESFiled Nov. 26, 1934 4 Sheets-Sheet 1 In venlvr Frank}? Wald.

w. ma suam iyiE Tt-m F. E. WOLD SERVICING EQUIPMENT FOR VEHICLES 4 FiledNov. 26, 1954 4 Sheets-Sheet 3 Inventar Fran/1'17 Z00 Zd Searcn nounDec. 1, 1936. WOLD 2,062,549

SERVICING EQUIPMENT FOR VEHICLES Filed Nov. 26, 1954 4 Sheets-Sheet 4 Al/ /-m fnflenlar Franlrl. Wald.

Hits-i Patented Dec. 1, 1936 UNITED STATES hearse soar PATENT OFFICESERVICING EQUIPMENT FOR VEHICLES Frank E. Wold, Santa Monica, Calif.

Application November 26, 1934, Serial No. 754,836

3 Claims. (Cl. 73-51) This invention relates generally to servicingequipment for vehicles, and is more particularly concerned with meansfor controllably rocking or vibrating a vehicle while it is beinglubricated.

It is well recognized that in lubricating leaf springs, shackle-boltsand other movable joints of a vehicle, there is a decided lack ofpenetration of the lubricant to the rubbing surfaces unless the jointsbe moved during the lubricating operation. This is particularly true ifthe joints be tight, even though a high pressure lubricating system beemployed. For instance, a tight shackle-bolt connection may absolutelydefy penetration unless joint-movement be set up through the use of acrowbar or the like.

It is therefore among the objects of my invention to provide servicingequipment whereby a vehicle may be continuously rocked or vibratedduring the lubrication thereof, thus insuring efficient distribution ofthe lubricant between the rubbing surfaces of all movable joints. Thisis accomplished by elevating the vehicle on a hoist, mounting on thehoist an automatic vibrating mechanism (operated, for instance, by airunder pressure) and applying the vibrator thereof to any suitableportion of the vehicle, the vehicle axles preferably having first beenstrapped to the hoist.

The equipment may also be used to advantage in disclosing loose bodybolts and the like and in locating frame or body squeaks, for as thevehicle is rocked by the vibrator these conditions are sufiicientlyaggravated to render them readily locatable by the operator.

As a further feature of the invention, the vibrating mechanism ismounted on the hoist itself, rather than being supported at the groundsurface and extending upwardly therefrom to the vehicle frame, itresulting that the hoist is not put under the wracking andplunger-bending strains which would necessarily occur were the spreadingefiect, existing during the up-stroke of the vibrator, to be appliedbetween the fixed ground surface and a vehicle mounted on the hoist.

As a further feature of the invention, the vibrating mechanism isreadily attachable to and detachable from the hoist, and the mounting issuch that when the mechanism is applied to the hoist, the vibratorthereof may be applied to practically any selected part of the vehicle,whether or not that part directly overlies the hoist superstructure.Since the vibrating mechanism is readily detachable from the hoist, thelatter may be lowered to the ground level and the vehicle rolledthereover or therefrom without any diminished clearances and yet, afterthe hoist has been elevated with the vehicle thereon, the vibratingmechanism may be applied to the hoist and to the vehicle in such amanner that the vertical clearance then existing below the hoist isutilized to accommodate the lower part of the vibrating mechanism, thusmaking it possible to have that mechanism of a size and character bestadapted to the task in hand.

I have also devised and illustrated a particularly effective vibratingmechanism, a hanger therefor, and means for strapping the vehicle axlesto the hoist, each of which features is made the subject matter ofcertain of my claims, but the novel aspects and advantages thereof maybe pointed out to better advantage in connection with the followingdetailed description, reference being had to the accompanying drawings,in which:

Fig. 1 is a side elevation showing my servicing equipment in operativecondition;

Fig. 2 is an enlarged, fragmentary section on line 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmentary section on line 33 of Fig. 2 butshowing only that portion of the structure which lies about the rearaxle of the vehicle;

Fig. 4 is an enlarged plan section on line 4-4 of Fig. 1 and as taken onthe plane of line 4-4 in Fig. 9, certain overlying parts being shownfragmentarily in full plan;

Fig. 5 is a section on line 5-5 of Fig. 4;

Fig. 6 is a view similar to Fig. 5 but showing the parts in changedposition;

Fig. 6a. is a fragmentary section on line 6a-6a of Fig. 6;

Fig. 7 is a fragmentary section on line 1-1 of Fig. 6;

Fig. 8 is a longitudinally contracted side elevation of the vibratingmechanism, with the cylinder casing shown in sections as taken on line88 of Fig. 4, and certain of the parts within that casing being shown inbroken-away section in order to better illustrate their construction;

Fig. 9 is a view generally similar to Fig. 8 but showing the parts inchanged position and also showing a portion of the telescopic piston rodin broken-away section;

Fig. 10 is a fragmentary section, partly in elevation, of the adjustingnut when it is spread open to permit coarse adjustment of the jackscrew;

Fig. 11 is a section on line Il-ll of Fig. 9;

Fig. 12 is a perspective view of a hanger used in connection with thesupport of the vibrating device;

Fig. 13 is an enlarged elevation, partly in section and with a portionof the chain broken away, of my improved clamping or strapping device;and

Fig. 14 is a section on line I 4l 4 of Fig. 13.

In Figs. 1 and 2, I have illustrated a hydraulic or power hoist H whichmay be of any suitable construction but is here illustrated as includinga usual plunger-piston I and a superstructure H consisting of side railsI2 of I-cross-section fastened centrally to plunger-plate l3 and thencediverging as indicated in Fig. 2. At one end a cross plate I4 is securedto the top of the side rails, the plate being centrally recessed at IEto take differential casing l6 of vehicle V. The opposite ends of thesiderails carry usual sliding blocks l1 upon which rest the front axle18 of the vehicle In order that reference later may be made to variousparts of the vehicle, I will here designate such parts as follows: rearaxle housing 19, chassis springs 20, shackles 2| and frame rails 22.

Either or both axles are preferably strapped down to the hoist, leavingall parts of the vehicle which are spring-supported from these axles ortheir immediately associated parts, free from movement under theinfluence of the vibrator, to be described. While the straps S may be ofany suitable type and may be applied at opposite ends of each axle or atonly one or two of these points, as chosen by the operator, I have hereillustrated, and will later describe, a particularly efficient and noveltype of strap and have indicated both axles as being strapped down.

My improved automatic vibrating or reciprocating mechanism is generallyindicated at A and preferably is removably suspended from the hoist bysuch means as a support or hanger generally indicated at B (Figs. 1, 2and 12). Again, while the broader aspects of the invention are notlimited to particularities of the hanger, I have disclosed an entirelynovel hanger which is particularly efficient and therefore is thesubject matter of certain of the appended claims.

The hanger, which is adapted to be applied to the hoist after the latterhas been raised to allow suflicient vertical clearance and to bedetached before the hoist is lowered, consists of a continuous rod bentto provide a rail-engaging head 23 and two horizontally spaced andaxially alined hooks or trunnion-bearings 24. The horizontal portions 25of the head are adapted to rest on top of one of the rails l2, theseportions being bent downwardly and inwardly at 26 to provide hooks forengaging the underside of the inner flange 21 of rail [2, bends 26 beingconnected by bar-portion 28. Vertical legs or suspension members 29 are,adapted to engage the outer flange edges but are preferably bentoutwardly at 30 to offset the trunnion-bearings 24 with respect to railI2 and thus provide increased horizontal clearance with respect to thatrail. This clearance is preferably of a magnitude to allow inwardswinging movement of those parts of the vibrating mechanism which extendupwardly past the rail and to bring the vertical axis of that mechanisminto the most advantageous position with respect to the vehicle frame,as will hereinafter be made apparent, legs 29 preferably being of alength to bring trunnion-bearings 24 well below superstructure ll.

The hanger, with its vibrating mechanism, is adapted to be applied toand removed from the hoist when the latter is in an elevated position.Consequently, when the hoist is at the ground level G, the vibratingmechanism presents no interference to the normal operation of rolling acar onto or from the hoist.

However, after the hoist is raised and the hanger and mechanism A areapplied thereto, considerable vertical clearance exists between theunderside of the vehicle and the lower end of said mechanism (muchgreater than would be the case if the Vibrating mechanism were mounteddirectly on the hoist-rail) and, accordingly, the vibrating mechanismmay be of a size and character best adapted to apply proper vibratorymotion to the vehicle. The relatively low position of trunnion-bearings24 also increases the range of bodily movement of the vibrating unit sothe vibrator thereof may be applied to parts of the vehicle whichotherwise would be inaccessible.

The hanger may be applied to any desired part of thehoist-superstructure and hence beneath any desired part of vehicle V,and of course, once it is applied, it may later be easily slid along thehoist rails to various other selected positions.

Vibrating mechanism A includes a cylinder 33 of which the bottom head 34is illustrated as being integral with annulus 35, whereas the upper head36 is in the form of a detachable cap held to annulus flange 3'! by capscrews 38. Piston head 39 (preferably, though not necessarily, providedwith split-spring sealing rings 46 or the like) divides the cylinderbore into upper and lower chambers 4| and 42, respectively, cap 36having an integral valve block 43 depending into upper chamber 4|. Cap36 also carries diametrically opposite trunnions 44 (Fig. 4) adapted tobe taken in hanger-bearings 24, end flange 45 on the trunnions insuringagainst the hanger arms being sprung apart in a manner accidentally tofree the cylinder from the hanger. Of course it lies within the scope ofmy invention to provide the trunnions or other hangerattachment means onother parts of the cylinder 33, but the illustrated placement of thetrunnions has been found well to serve the purpose.

The piston rod or vibrator. generally indicated at 46 is, in effect,telescopically adjustable whereby its effective length may be varied. Itincludes a tubular portion 41 secured in any suitable manner to head 39as by screwing it at 48 over the central head-stem 49. Tube 41 is guidedin its vertical movement through cap 36 by sleeveflange 50, and islongitudinally slotted at to take the head 52 of bolt 53 which extendsthrough valve-block 43 and is positioned by nut 54 (Figs. 4 and '7). Thebolt, whose head 52 forms a key slidable through key-way 5|, is insertedfrom the bore of tube 41 before head 39 is applied to said tube, andthereafter serves not only as a positive stop for limiting the up-strokeof the piston (beyond the limit established by the valve-action to bedescribed) but also prevents relative rotation between the tube portionof the piston rod and the cylinder so that the valve actuatingmechanism, parts of which are secured to the piston and other parts ofwhich are secured to the valve-block, may not be relatively rotated in amanner to displace said parts or put them under undue strain.

Secured to the upper end of tube 4! is a sleeve 55 whose bore 56 isadapted slidably to take the adjustment nut assembly 51 whereby thejackscrew portion 58 of piston rod 46 may be extended or retracted withrespect to tube 41, thereby to vary the efiective length of the rod.con- MEASURlNG..e TSTiNG.

sidered as a whole. The upper end of screw 58 carries a slotted head 59.Saddle 60, in the form of a bar having upstanding lugs 6| at its endsand a plurality of intermediate adjustment holes 63, is adapted to beheld in the head-slot by bolt 62 which is extended through any selectedhole 63.

Nut assembly 51 includes a ring 64 (Figs. 9 and 11) having a conicalcounter-bore 65 into which diametrically-opposite pins 66 project. Nut61 is of the split type, the symmetrical halves 68 thereof each having ahead portion 69 provided with a hand grip I0, a downwardly taperingwedge portion 'II, and a semi-cylindrical neck portion I2, the latterbeing taken in ring bore 65. The opposed edges of neck portions I2 havesemi-circular recesses I3 to take pins 66 whereby there is formed aloose pivotal connection between ring 64 and the nut-halves 68. Thethread in each nut-half extends only through the head and wedgeportions, the remainder of the bore and the conical counterbore I4 beingsmooth.

Normally, and also when the load is supported on saddle 60, nut-assembly51 is in the condition of Figs. 9 and 11, the annular and downwardlytapering shoulder I5 of sleeve 65 engaging wedge faces II to force thenut-halves together and therefore operatively engaging the nut threadswith jack-screw 68. Preferably, the angle of shoulder I5 is a littlesteeper than that of the side-faces of the threads. Washer 16 is securedby bolt 11' to the lower end of the jack-screw, this washer not onlyserving roughly to center the lower end of the jack-screw but also toprevent the nut assembly from dropping clear of the jack-screw when thelatter is bodily removed from tube 41.

When it is desired to secure a rapid extension of the piston rod, suchas in making an initial coarse adjustment, it is merely necessary topull the jack-screw up, which action, through the thread-engagement,raises nut assembly 51 with respect to sleeve and hence raises wedges'II with respect to the shoulder 15, allowing the nuthalves to spreadapart (as they have normal tendency to do by reason of the outwardlyoffset relation of their centers of mass with respect to their pivotpoints) clearing the nut threads from the jack-screw (see Fig. 10) andthus allowing the screw to be lifted with respect to the nut. Theopposed edges 11 of the nut-halves are cut back at points below pins 66,which provision, as well as the tapers of bores and I4, allows ampleswinging movement of the nut-halves to clear the threads. While thejack-screw is thus being lifted there is a repeated tendency for thenut-halves to drop as the individual nut and jack-screw threads passeach other, thus giving a ratcheting effect, but this does not delay theoperation.

When the screw has been pulled up to the desired height under thiscoarse adjustment, it

is released by the operator, and nut assembly 51 drops back to theposition of Fig. 9, annular shoulder I5 re-engaging wedgev faces II toforce the nut-halves back into operative engagement with the jack-screw.Thereafter, by rotating nut 61 through handles I0, the screw may befurther projected to secure the desired fine adjustment.

Conversely, if it be desired quickly to collapse the piston rod, it ismerely necessary to lift the jack-screw slightly until the nut-halvesare spread and then manually hold the nut in that position while thescrew is lowered freely or allowed to drop through the nut.

I will now describe the valves and their actuation whereby air underpressure and connected to the cylinder is controlled in a manner to setup reciprocation or vibratory movement of the piston rod or vibrator.

Valve block 43 is substantially L-shaped as viewed in plan (Fig. 4) andin the longer leg 18 thereof there are provided the horizontallyextending and axially alined valve chambers I9 and (Fig. 5). Opening tochamber I9 is a vertical passageway 8| which communicates at its upperend with horizontal passage 82, the latter opening to the peripheraledge of cap 36 and being adapted to take fitting 83, preferably in theform of a valve or stop-cock, the hose 84 (Fig. 2) applied to this valveleading from any usual source of air under pressure.

Opening into valve chamber I9 is passage 85, valve ball 86 beingadapted, at times, to be urged by spring 81 into the seated position ofFig. 6, where it closes oif communication between chamber I9 and 85.Extending upwardly from chamber is passage 08 which is connected byhorizontal passage 89 in cap 36 to vertical passage 90 extendingdownwardly through annulus 35 to horizontal passage 9| which opens atport 92 to cylinder chamber 42 beneath piston head 39. Preferably, head39 has a central boss 39 which engages end-wall 34 positively to limitthe downstroke of the piston (beyond the limit established by the valvemechanism to be described) and thus insure immediate admission of air tochamber 42 after a period of non-use. The passage system thus fardescribed may be considered generally as an air inlet channel I,controlled by valve 86.

Exhaust channel E includes a horizontal passage 93 opening at port 94from chamber 42 and communicating with vertical passage 95 which extendsthrough annulus 35 and opens into horizontal passage 96 in cap 36.Passage 96 opens to vertical passage 91 in valve block 43, and isthereby put into communication with valve chamber 80, the outlet orifice98 of this chamber being adapted to be closed, at times, (Fig. 5) byvalve ball 99 under the pressure of spring I00. Orifice 98 opens to slotIOI which is cut in block 42 and is, in turn, open to cylinder chamber4|, the latter being constantly open to the atmosphere through the boresof nipples I02 in cap 36 (Figs. 4 and 8).

Valve tappet I03 is arranged in slot MI and is in the form of angularextension on rock shaft I04, the latter being mounted for oscillation inbore I 05 of the shorter valve-block leg I05 (Fig. '7). Tappet I03 issubstantiallly semi-circular in cross section, the flat face I0'Ithereof being angled off as clearly shown in Figs. 5 and 6, while thearcuate face preferably carries a hardened tip I00 adapted, at times, toengage ball 99 and thrust it from its seat against the action of springI00. The oscillatory stroke of tappet I03 is limited by the engagementof its opposite faces With the opposed defining walls of slot IOI.

Extending axially through passage 85 and bore I09 in block 43 and thenceinto slot IOI in the path of tappet I03, is tappet rod IIO. Mounted foroscillation on rock shaft I04 is a link or lever I I I (Figs. 7 and 8)which preferably has a sleeve II2 having internal bearing on the shaftand external bearing in block-counterbore I I3. Nonrotatively fixed onthe end of shaft I04, as by square H4 and nut H5, is ahead H6, in theperipheral face of which is socket II'I. Pivotally connected at II8 tothe outer end of link III is a pair of links I I 9 (Figs. 4 and 8), thelower ends of the latter being pivotally connected at I20 to post I2Iwhich is threaded at I22 into piston head 39.

A snap-actuator generally indicated at I23 is applied to link III andhead II6 whereby rock shaft I04 and tappet I 03 are snapped from theposition of Fig. 8 to that of Fig. 9, and vice versa, upon piston 39reaching predetermined positions within the cylinder 33. This actuatorcomprises telescopically arranged pin and sleeve I24, I25, respectively,the one having a spherical head I26 seated in socket II! and the otherhaving a spherical head I21 seated in socket I28 provided in post I29,said post being fastened to link or lever III by nut I30 (Fig. 4).

In discussing the action of the actuator and control means therefor, IWill refer to a certain line of centers and for this purpose I willdesignate the axis of shaft I04 as center I04 and the centers of headsI26 and I2! as I26 and I2'I', respectively,

Compression spring I3I constantly tends to extend the pin and sleeverelatively, and thus, when the piston head is at its lower limit oftravel, the parts occupy the positions shown in Fig. 8 and, since centerI26 is above the line of centers I04I21', the spring exerts through pinI24 such pressure on head II6 as to tend to rotate it in a clockwisedirection, thus holding tappet I03 in the position of Fig. 5, where itacts through tappet rod IIO to hold ball 86 off its seat against thepressure of spring 81.

Now assume that the servicing equipment is to be put to use. After thevehicle has been lifted by the hoist and its axles have been strappedthereto, hanger B is applied to one of the rails I2 and vibratingmechanism A is mounted on the hanger as illustrated in Figs. 1 and 2.Piston rod 46 is then extended (by the coarse and fine adjustmentsspoken of before) until saddle 60 is firmly applied to a chosen part ofthe vehicle, for instance, to one of the frame rails 22. Thisapplication may be such as shown either in full or dotted lines in Fig.2, it being noted that the pivotal mounting of the vibrating mechanismon the hanger allows said mechanism to be swung from vertical so thevibrator or piston rod may reach and be applied to points of the Vehiclewhich may be out of vertical alinement with the trunnion-bearings of thehanger.

When valve 83 is opened, air under pressure flows through the followingcourse;--passageways 82, 8|, I9, 85, 88, 89, 90, 9I and thence throughport 92 into cylinder chamber 4I beneath piston head 39, thus raisingthe latter and projecting piston rod or vibrator 4B in a manner to liftthat part of the vehicle to which it is applied. Of course, during thispart of the cycle, spring I holds exhaust valve 99 closed to prevent theescape of high-pressure air, the air in chamber 4I above the pistonbeing exhausted through the bores of nipples I02.

As the piston head travels upwardly, the control-linkage III, II9 foldstogether or angularly closes, and centers I21, I26 and I04 are graduallybrought into line, causing telescopic contraction of the pin and sleeveassembly I24, I25 and longitudinal compression of spring I 3|. As theline of centers I2'I-I04 passes above center I26 (which is calculated tooccur at the predetermined stroke-limit of the piston head) spring I3Ibecomes effective to project pin I24 in a manner to snap head H6 andhence shaft I04 in a counter-clockwise direction to the position of Fig.9. This movement snaps tappet I03 to the position of Figs. 6 and 6a,allowing valve 86 to close and thus out 01f further inlet flow of air tochamber 42, while tip I08 opens valve 99 against the pressure of springI00. The weight of the car is then free to depress the piston, the airbeneath head 39 being exhausted through the following channel;passageways 93, 95, 96, 91, 80, orifice 98, slot ml and chamber 4I,whence it passes to the atmosphere through the bores of nipples I02.

The downward movement of head 39 gradually spreads linkage III, H9, andas the line of centers I21-I04 passes below center I26, spring I3Ibecomes effective to snap head II6, shaft I04 and tappet I03 back to thepositions of Fig. 8, thus closing exhaust channel E and reopening theinlet valve 86 to cause a reoccurrence of the described cycle ofoperation.

Reciprocation of vibrator 46 thus continues as long as valve 83 is open,and the rocking or vibratory effect given to the vehicle opens andcloses leaf springs 20, works the shackle-bolt connections, and sets upsuch general movement of the vehicle parts as to enable the fullpenetration of lubricant applied to the various joints by the operatorwhile the vehicle is subjected to the vibratory movement. The pivotalmounting of the vibrating mechanism on hanger B allows the vibratingmechanism to swing and thus accommodate itself to such pivotal movementas the vehicle frame may have during the travel of the piston. Forinstance, since the vibrator is usually applied to the vehicle frame atone side of its vertical axial plane, the frame will be given a tiltingor pivotal movement about an axis at the far side of said vertical axialplane.

The stroke of the vibrator, as determined by the valve timing, may bevaried by altering the effective length of link or lever III throughattachment of links II9 thereto at difierent selected pin holes I I8.

Nipples I02 serve not only to maintain chamber M in communication withthe atmosphere but also serve as inlets through which lubricants may beintroduced to chamber 4I. Since the entire valve mechanism is withinthis chamber, it is kept efficiently lubricated by this single body ofoil, both by splash action and by the oil spray set up through theintermittent jetting of air from orifice 98. Should any of the oil leakdown into chamber 42 during periods of non-use, it is promptly forcedback into the upper chamber through exhaust channel E as soon as thevibrator is operated.

I will now describe the illustrated and preferred form of strap fortieing the vehicle axles to the hoist. Chain I34 is secured at one endI35 (Fig. 13) to equalizer bar I36 which is in the form of two strapsI31 secured together at I38 near their ends and centrally spread to forma yoke I39, though it will be understood it lies within the broaderaspects of the invention to form the yoked equalizer bar of a singlepiece.

Nut I40 has two of its diametrically opposite corners turned down toprovide trunnions I4I which have bearing in strap-holes I42 to providefor pivotal movement of the nut with respect to the yoke. Clamping screwI43 extends through the nut, carrying at one end an operating crank I44and at the other end a rotatably mounted clamp head I45, screw I46extending into groove I41 in member I43 to act as a key preventingaccidental longitudinal separative movement between screw I43 and head I45 but permitting relative rotational movement therebetween. Screw I46is adapted to be withdrawn Wi MEASURING 62 I531 ENG.

from groove I41 when assembling and disassembling the device.

In Figs. 2 and 3, I have shown an efficient manner of applying strap S,though it will be understood this showing is merely illustrative and notlimitative. With equalizer bar I36 held so it extends diagonally beneathrail I2, chain I34 is thrown up along the inside of the rail, over theedge of plate II4, over axle housing H9, and thence brought down overthe outer face of the rail, one of the chain links I48 near the free endof the chain being engaged with downwardly opening hook I49 on bar I36.Jack-screw I43 is then actuated to engage head I45 with the underside ofrail I2, continued actuation of the screw acting through bar I36 totighten the chain and thus firmly tie the axle to the hoist. With thistype of tie, the anchoring and freeing operations may be accomplishedwith ease and dispatch and yet the tie is secure and dependable.

While I have shown and described a preferred embodiment of my invention,it Will be understood the drawings and description are to be consideredas illustrative of and not limitative on the claims appended hereto, forvarious changes in design, structure and arrangement may be made withoutdeparting from the spirit and scope of those claims.

I claim:

1. In combination with a vehicle hoist embodying a pair of spacedvehicle supporting beams and means for elevating them, a hanger havingan upper hook end applicable to either of the beams either to hang ontheir exterior faces or their interior faces and at any point in theirlengths, and having a depending portion with spaced trunnion receivingopen hooks at its lower end, and a single unitary vibrator mecha-;,

nism embodying a cylinder and piston, trunnions projecting at oppositesides of the cylinder and adapted to removably rest in the open hooks ofthe hanger, a hollow piston rod extending up from the piston, a jackscrew in and carried exclusively by the piston rod, a vehicle engagingshoe on the upper end of the screw, and a 'nut carried by the piston rodand releasably engaging the threads of the screw; said vibratormechanism, including the parts'hereinabove described, being removable asa unit from the hanger.

2. In an automatic vibrating mechanism, a cylinder, a piston head in thecylinder, a piston rod extending from the head to the exterior of thecylinder, and a vehicle-engaging member on said rod, said rod embodyinga tube, a jack screw extending into said tube, a ring extending withinsaid tube, a split nut extending within said tube and said ring, the twohalves of said nut being pivotally connected to said ring whereby theyare movable to and from position of operative engagement with the jackscrew, said ring and said nut being longitudinally and rotativelymovable relative to the tube, and means on the tube coacting with thenut normally to hold said halves in such operative engagement.

3. In combination with a vehicle hoist embodying a pair of spacedvehicle supporting beams and means for elevating them, a hanger havingan upper end applicable to either of the beams at different points intheir lengths, and having a depending portion with spacedtrunnion-receiving bearings at its lower end, and a single unitaryvibrator mechanism embodying a cylinder and piston, trunnions projectingat opposite sides of the cylinder and adapted to bear in the hangerbearings, a longitudinally extensible piston rod extending up from thepiston, and a vehicle engaging shoe on the piston rod.

FRANK E. WOLD.

